Guys, your expert assistance is required.

Recently finished a rebuild of a 454 for my 69 Camaro. The failure was lifters and cam. I have a new cam, lifters and roller rockers in it. It ran perfectly for the first 150 miles, then on the way home from a running in trip it developed a loud lifter noise at about 2500 rpm. I let it idle down and it disappeared then after 5 mins of driving at over 2200 rpm it returned. Limped home. I pulled off the intake manifold, and noticed that one lifter had spat out the retaining clip. thought this was the issue, changed the clip rechecked the valve set banged it all together and went out for another run in trip. The car ran perfectly for the first half and hour, but once fully up to temprature and after more than 5 minutes the lifter sound returned, clutched it the sound remained as it idled down then disappeared shortly after clutch back out and after about a minute of 2300rpm the sound returned. Just wondering if there are any potential sources for oil pressure issues at longer periods of sustained use at this rpm range. It only seems to be in the bank 1 - 7. In addition there are times it will just come and go on its own. I am wondering if this type of oil problem caused the failure of the previous cam and lifters. the guage shows i have good oil pressure at this point. I am running 25/60 penrite oil in it. Any thoughts on what might be happening?

 

Are you breaking the valvetrain in properly?

 

25/60 oil is a bit on the thick side IMO. That hevy stuff will give oil pressure, but it does not mean it is flowing properly, 10/40 syntethic may be a better choice.

 

Green machine, I believe so, I have followed the info given to me with the lunati cam.

 

Z28pete, am changing the oil tomorrow as it has done the initial run in. Will try for a lighter oil and see what happens.

 

So i take it there are no known cavitation or aeration issues common to big blocks that may cause this, or common issues that would leave bottome end oil pressure but rob upper cylinder lubrication?